Manhole closing arrangement

ABSTRACT

A closing arrangment for manholes and similar hatches defined by a coaming, includes a yoke which extends across the coaming, a cover being suspended from the yoke and being adapted to be pressed by the yoke downwardly against the coaming. One end of the yoke is detachably connected with the coaming by means of a horizontally pivotable catch, while the other end of the yoke is connected to the coaming by means of a pair of interengaged sliding elements respectively connected to the coaming and to the yoke so as to permit a vertically and angularly relative movement of these elements for a raising, lowering and angular movement of the cover.

Unite States Patent. {1 1 Hover [451 Oct. 15,1974

[ MANHOLE CLOSING ARRANGEMENT [76] Inventor: Nils Th. Hover, Bygdoy Alle98, Oslo, Norway [22] Filed: Oct. 31, 1972 [21] Appl. No.: 302,394

[51] Int. Cl. E05c 15/00 [58] Field of Search 114/203; 292/256.5

[56] References Cited UNITED STATES PATENTS 938,593 11/1909 Laubeuf .f.114/203 2,224,292 12/1940 Dwyer 292/2565 2,816,683 12/1957 Miers et a1292/2565 Primary Examiner-Geo. V. Larkin [57] ABSTRACT A closingarrangment for manholes and similar hatches defined by a coaming,includes a yoke which extends across the coaming, a cover beingsuspended from the yoke and being adapted to be pressed by the yokedownwardly against the coaming. One end of the yoke is detachablyconnected with the coaming by means of a horizontally pivotable catch,while the,

other end of the yoke is connected to the coaming by means of a pair ofinterengaged sliding elements respectively connected to the coaming andtothe yoke so as to permit a vertically and angularly relative movementof these elements for a raising, lowering and angular movement of thecover.

6 Claims, 7 Drawing Figures PAIENTEDOBI I 51974 sum 1 or 2 MANHOLECLOSING ARRANGEMENT The present invention relates to an arrangement forthe closing of manholes or similar hatches which are defined by acoaming which may form a sealing surface against a cover. Such openings,which are required for the purpose of inspection and/or maintenance intanks or other closed spaces adapted for storing and/or transport ofliquids or gases, may be of highly different circumferential shape, andthe covers used for the closing may have a plane or other surface,according to the stresses to which the cover is to be subjected.

The closing systems of such openings must satisfy a number ofrequirements. The sealing must be good, closing and opening must beperformed in a simple manner with the least possible consumption ofenergy, the system must not comprise loose parts which may easily goastray, and the cover must not in open condition form any obstacle andneither must it be unintentionally movable. A previously usual system,having a number of pin screws distributed along the circumference of thecoaming, and corresponding holes in the cover edge and a correspondingnumber of nuts, does not satisfy nearly any of the requirementsmentioned, and the same is the case with covers which are hinged on thecoaming about an axis in the plane of the cover, as the sealing in suchdoor structures can scarcely be faultless. 1

Further, a system is known in which a loose cover is pressed downagainst the hatch coaming by a centrally attacking screw which isengaging a yoke which is carried across the hatch and at one end hingedon the hatch coaming about a horizontal axis and at the other endengages a loop on the hatch coaming. Thus, in this system slso, thecover forms a loose unit, and the yoke required a great free heightabove the hatch for its pivotal movement.

The present invention relates to a closing system of the type whichcomprises a yoke which extends across the hatch and is adapted to pressa cover against the hatch edge, but is distinguished from the previouslyknown closing systems therein that the cover is centrally suspended inand maybe lifted, lowered and set bymeans of the yoke which isdetachably connected to the hatch coaming at each end. Due to the factthat the cover is suspended in the yoke, the two members form one unit,wherein the members cannot be lost relative to each other, and thedetachable connections at both ends of the yoke may be so made that oneconnection, as known perse,'forms a hold-down, while the other forms amechanism which permits both movement in a direction at right angles tothe plane through the cover, ie a setting or an opening movement,respectively, and a pivotal movement of the yoke with the suspendedcover in a plane extending parallel to the plane through the cover.

The suspension of the cover on the yoke may suitably be so made that theyoke is provided with a projection directed towards the cover andprovided with a hole which is oblong in the direction towardsthe coverand adapted to receive a pin which extends through two uprights on thetop surface of the cover, to either side of 'the yoke projection,whereby yoke and cover are provided with a certain motion liberty, atthe same time as the setting force is transmitted from yoke to .coverthrough the yoke projection which abuts against the surface of thecover, whilethe cover pin is without stress when the hatch is closed.

The connection between one end of the yoke and the coaming mayconveniently be in the form of a jack device, in which one part issolidly connected to the coaming and the other part is connected to theyoke and may be moved rectilinearly relative to the stationary part, atright angles to the plane through the cover and pivot about an axis ofthe rectilinear movement, so that the yoke with the suspended cover maybe lowered and lifted relative to the coaming and be pivoted outwardlysideways of the coaming.

Further features and advantages of the system according to the inventionwill appear from the following description of a preferred embodiment ofthe system, and from the claims.

The accompanying drawings schematically illustrate an example of how asystem according to the invention may be designed.

FIG. 1 is a side view of the system with its hatch coaming, in closedcondition.

FIG. 2 is a plan view of the system, in closed condition.

FIG. 2A is a sectional view,.at a slightly enlarged scale, taken alongthe line 2A--2A of FIG. 2.

FIG. 3 is a side view of the system in open condition.

FIGS. 34; and 3b are sectional views through alternative sealing meansbetween cover and batch coaming.

FIG. 4 is an axial sectional view of the jack'device.

In the drawings,] is the top wall of a tank which may be adapted forstoring or transport of liquids or gas, such as aboard a ship. For thepurpose of inspection or for other purposes the tank is provided with ahatch which is defined by a coaming 2 and which is to be sealinglyclosed by means of a cover 3. The hatch and its coaming may have anycircumferential shape and the cover may be of various designs. In theexample shown,

it is presumed that the hatch coaming is circular and.

that the cover is plane and provided with reinforcing ribs 4. Along thecircumference of the coaming 2 and the cover 3 there is provided singleor double sealing means, as shown in FIGS. 30 and 3b, respectively,comprising a gasket 5 made of a material and ina shape which depend onthe substanceto be held in the tank and the vapor from the same.

For the purpose of positioning and setting the cover 3 on the coaming 2,there is provided a yoke 6 extending across the hatch centrally relativeto the cover 3, the yoke being provided with projections 7 which extendtowards the cover 3. Each projection is provided with an oblong hole 8for the reception of a pin 9 provided on each of a pair of uprights 10on the cover. FIG. 2A illustrates the details of such arrangement.

At one end, to the right in F110. 1, the yoke 6 is adapted to co-operatewith a pair of plates 11 which are hinged at 12 to a bracket 13 on thehatch coaming 2. In the example shown, plates 11 are provided with a pin32 which may co-operate with a corresponding recess in the top face ofthe yoke 6. At this end, the yoke is also provided with a forkedprojection comprised of plates 14 adapted to cooperate with the bracket13 on the hatch coaming for the guidance of the yoke 6. Plates 14 aresecured toopposite sides of the yoke as in FIG. 2.

At the other end, to the left in FIG. 1, the yoke 6 is provided withcars 15 having holes 16 (shown in FIGS.

3 l and 3) for hinge connection to the movable part of a jack which isgenerally referenced 17. Such connection is effected by means of pins23.

The jack 17 comprises a cylindrical member 18 which encloses a secondcylindrical member 19 and may be moved axially and rotated relative tothe latter. The axial movement is effected by means of a screw threadedbar 20 attached to a hand wheel 21, engaging a nut 22 which is fixedlyconnected to the inner cylinder 19. The screw' threads of the bar 20 andof the nut 22 conveniently are of the self-locking type, so that theconnection between the bar and the nut cannot be influenced byvibrations or shocks in the plant as a whole. The yoke 6 is connected tothe outer cylinder 18 through pins 23 and the inner cylinder 19 isfixedly connected to brackets 24 on the hatch coaming. At the lower end,the outer cylinder 18 is provided with a pair of diametricallypositioned projections 25 adapted to co-operate with correspondinglypositioned recesses 26 provided in a collar or the like 27 which issecured to the inner cylinder 19. The projections 25 and the recesses 26are so shaped for interengagement, and for avoiding spark provokingshocks which may occur when they are entering into engagement with eachother. The projections 25 and the recesses 26 form a claw coupling whichcan angularly lock the cylinders 18 and 19 relative to each other, atthe same time as the cylinders are freely rotatable relative to eachother upon an initial axial movement of the outer cylinder 18.Obviously, the jack 17 is provided with antifriction discs and ashoulder 28, and the two spaces 29 and 30, respectively, may be filledwith a suitable oil, grease or the like, for the purpose of assuringlasting sealing and friction conditions.

Below ears 15, the yoke is provided with an arm 31 extending downwardlyand adapted to contact the outer surface of the movable member 18 of thejack 17.

The system of the invention may be used in the following manner.

Under the conditions illustrated in the FIGS. 1, 2 and 3a, 3b, with thecover 3 in place upon the coaming 2 and the yoke 6 in place, the pin 32of plates 11 is in engagement 'with'its corresponding recess in the yoke6. Projections 7 on the yoke 6 are in contact with the top surface ofthe cover 3, with the pins 9 on the cover in free engagement with thehole 8 in the projection 7. The other end of the yoke 6 is in engagementwith the pins 23 on the outer cylinder 18 of the jack 17.

Through rotation of the hand wheel 21, the cylinder 18 and thereby thisend of the yoke 6 is then moved downwardly relative to the secondcylinder 19, i.e. relative to the coaming 2. Hereby, the recess at theright hand end of the yoke 6 is applied against the pin 32 of plates 11,projections 7 press against the top surface of the cover 3, the gasketsare sealed and the claw coupling 25, 26 is closed. The more the handwheel 21 is rotated, the more the cover 3 is pressed against thecircumference of the coaming 2, with a force applied at thecircumference which depends upon the lever arm present, i.e. thedistance between the pins 23, projections 7 and plates 11, so that asealing pressure in the gaskets 5 is provided which is twice the settingforce of the jack l7.

When the hatch is to be opened, the hand wheel 21 is released and thejack member 18 with suspended yoke 6 is lifted, the projection 31 on theyoke 6 thereby contacting the cylinder 18, so that the yoke 6 bringsalong the cover 3 through engagement between pins 9 and the lower end ofthe holes 8 in projections 7. The sealing effect of the gaskets 5 isreleased. Eventually, plates 11 may be turned outwardly about pivot 12and the claw coupling 25, 26 is disengaged,'so that the cylinder 18 maybe rotated relative to the cylinder 19 and the cover 3, thereby swungoutwardly and, through a renewed lowering of the jack 17, adopt theposition shown in FIG. 3, in which the parts are again locked relativeto each other by the claw coupling 25, 26 without any danger ofunintentional swinging movement of the cover about the longitudinal axisof the jack 17.

When the hatch is again to be closed, the member 18 of the jack 17, withsuspended cover 3, is lifted until the claw coupling 25, 26 isdisengaged. The cover is the swung about the axis of the jack, which isagain lowered, and the cover assumes a correct position on the coaming 2guided by the fork l4 and the bracket 13, so that plates 11 maybe swungupwardly over the end of the yoke, for engagement between the loop pin32 and the recess in the top face of the yoke. At the same time, theclaw coupling 25, 26 begins to close, and the cover is ready for thesetting movement effected by rotation of the hand wheel 21, the coverpins 9 being freely received in the oblong holes 8 without transferringany force between yoke and cover. Thus, the claw coupling 25, 26 has atriple purpose. When the cover 3 is in an oubswung position, thecoupling locks the cover against unintentional swinging movement. Whenthe cover 3 is lifted, with disengaged coupling, the projections 25slide on the ridges between the recesses 26 during swinging movement ofthe cover, thereby maintaining the cover at a predetermined height untilthe projections 25 meet their recesses 26. The cover is then lowered andis accurately guided downwardly against the gaskets 5, with the fork l4guided by the bracket 13.

I claim:

1. A closing arrangement for manholes and similar hatches defined by acoaming, comprising a yoke extending across said coaming, a coversuspended from said yoke and being adapted to be pressed by said yokedownwardly against said coaming, one end of said yoke being detachablyconnected with said coaming by means of a horizontally pivotable catch,the other end of said yoke being connected to said coaming by means of apair of interengaged sliding elements respectively connected to saidcoaming and to said yoke, said elements being vertically and angularlymovable relative to one another thereby permitting a raising, loweringand angular movement of said yoke and said cover.

2. The arrangement according to claim 1 wherein said cover is suspendedfrom said yoke by means of at least one projection on said yokeextending toward said cover, said projection having a verticallyenlongated opening therein, and at least one upstanding ear member onsaid cover having a pin thereon extending into said opening.

3. The arrangement according to claim 1 wherein a guide plate is securedto said one end of said yoke at each side thereof, a bracket provided onsaid coaming, said guide plates engaging with opposite sides of saidbracket, and said catch being horizontally pivotable on said bracket andbeing releasably engageable with said one end of said yoke.

said locking means are in the form of a claw clutch.

6. The arrangement according to claim 4 wherein a vertically extendingbracket plate is provided at said other end of said yoke to facilitatemounting of said yoke to said one element.

1. A closing arrangement for manholes and similar hatches defined by acoaming, comprising a yoke extending across said coaming, a coversuspended from said yoke and being adapted to be pressed by said yokedownwardly against said coaming, one end of said yoke being detachablyconnected with said coaming by means of a horizontally pivotable catch,the other end of said yoke being connected to said coaming by means of apair of interengaged sliding elements respectively connected to saidcoaming and to said yoke, said elements being vertically and angularlymovable relative to one another thereby permitting a raising, loweringand angular movement of said yoke and said cover.
 2. The arrangementaccording to claim 1 wherein said cover is suspended from said yoke bymeans of at least one projection on said yoke extending toward saidcover, said projection having a vertically enlongated opening therein,and at least one upstanding ear member on said cover having a pinthereon extending into said opening.
 3. The arrangement according toclaim 1 wherein a guide plate is secured to said one end of said yoke ateach side thereof, a bracket provided on said coaming, said guide platesengaging with opposite sides of said bracket, and said catch beinghorizontally pivotable on said bracket and being releasably engageablewith said one end of said yoke.
 4. The arrangement according to claim 1wherein said elements comprises hollow tubes in telescopingrelationship, jack means for vertically moving one of said elementsrelative to the other, and cooperating locking means on each of saidelements for locking said elements into a predetermined angularposition.
 5. The arrangement according to claim 4 wherein said lockingmeans are in the form of a claw clutch.
 6. The arrangement according toclaim 4 wherein a vertically extending bracket plate is provided at saidother end of said yoke to facilitate mounting of said yoke to said oneelement.